calculations

calculations

[Henning Hraban Ramm]

Sorry, I skimmed the TeXbook for an hour but couldn't find how to do  
simple calculations in TeX...

This is a snippet from t-lilypond.tex:

\def\LPscale{0.6315789} % downscale the image
    \ifvmode
       \getfiguredimensions[\bufferprefix lilypond-\the\lily! 
figures.pdf][]%
%      \def\FigWidth{\LPscale\figurewidth}
       \leavevmode
       \ifdim\FigWidth>\localhsize
         \!!dimena=\localhsize
         \advance\!!dimena by-\FigWidth
         \noindent\hskip\!!dimena
       \fi
    \fi
    \externalfigure[\lily!img][scale=1000\LPscale]%
    \egroup%

I need to downscale every score to 63%, and the shown width check  
should use the corrected width.
How can I do that? (FigWidth should be LPscale * figurewidth)


Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[Hans Hagen]

Henning Hraban Ramm wrote:
> Sorry, I skimmed the TeXbook for an hour but couldn't find how to do  
> simple calculations in TeX...
>
> This is a snippet from t-lilypond.tex:
>
> \def\LPscale{0.6315789} % downscale the image
>     \ifvmode
>        \getfiguredimensions[\bufferprefix lilypond-\the\lily! 
> figures.pdf][]%
> %      \def\FigWidth{\LPscale\figurewidth}
>        \leavevmode
>        \ifdim\FigWidth>\localhsize
>          \!!dimena=\localhsize
>          \advance\!!dimena by-\FigWidth
>          \noindent\hskip\!!dimena
>        \fi
>     \fi
>     \externalfigure[\lily!img][scale=1000\LPscale]%
>   
does 

sx=\LPscale

work? 
 
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                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                             | www.pragma-pod.nl
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Re: calculations

[nico]

On Tue, 19 Sep 2006 22:53:18 +0200, Henning Hraban Ramm <hraban@fiee.net>  
wrote:

> I need to downscale every score to 63%, and the shown width check
> should use the corrected width.
> How can I do that? (FigWidth should be LPscale * figurewidth)

I don't know what you really want to do, but an example of computation  
could look like this:

\newdimen\myfigwidth
\newdimen\myfigurewidth
\def\myscale{.63}

\figurewidth=23pt
\myfigwidth=\dimexpr(\myscale\myfigurewidth)

\starttext
\the\myfigwidth
\stoptext

Regards,
BG

Re: calculations

[Henning Hraban Ramm]

Am 2006-09-19 um 23:34 schrieb nico:

>> I need to downscale every score to 63%, and the shown width check
>> should use the corrected width.
>> How can I do that? (FigWidth should be LPscale * figurewidth)
>
> I don't know what you really want to do, but an example of computation
> could look like this:
>
> \newdimen\myfigwidth
> \newdimen\myfigurewidth
> \def\myscale{.63}
>
> \figurewidth=23pt
> \myfigwidth=\dimexpr(\myscale\myfigurewidth)
>
> \starttext
> \the\myfigwidth
> \stoptext

Thank you, but now I always get:

! Illegal unit of measure (pt inserted).
<to be read again>
                    .
\figurewidth ->545.
                    03625pt
\dodostartlilypond ...expr (\LPscale \figurewidth
                                                   ) \ifdim \FigWidth  
 >\localh...

from the code:

\def\LPscale{.6315789} % downscale the image
    \ifvmode
       \getfiguredimensions[\bufferprefix lilypond-\the\lily! 
figures.pdf][]%
       \leavevmode%
       \newdimen\FigWidth
       \FigWidth=\dimexpr(\LPscale\figurewidth)
       \ifdim\FigWidth>\localhsize
         \!!dimena=\localhsize
         \advance\!!dimena by-\FigWidth
         \noindent\hskip\!!dimena
       \fi
    \fi
    \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
    \egroup%

What's wrong with \dimexpr{\SomeDef\SomeDim} ?
Some expansion problem?

(Sorry, I only try to patch the code, I didn't write it.)

Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[nico]

On Wed, 20 Sep 2006 00:04:33 +0200, Henning Hraban Ramm <hraban@fiee.net>  
wrote:

> Thank you, but now I always get:
>
> ! Illegal unit of measure (pt inserted).
> <to be read again>
>                     .
> \figurewidth ->545.
>                     03625pt
> \dodostartlilypond ...expr (\LPscale \figurewidth
>                                                    ) \ifdim \FigWidth
>  >\localh...

\figurewidth is not a dimension. I guess the following should work:

\def\LPscale{.6315789} % downscale the image
     \ifvmode
        \getfiguredimensions[\bufferprefix  
lilypond-\the\lily!figures.pdf][]%
        \leavevmode%
        \newdimen\FigWidth
        \newdimen\FigWidthReal=\figurewidth
        \FigWidth=\dimexpr(\LPscale\FigWidthReal)
        \ifdim\FigWidth>\localhsize
          \!!dimena=\localhsize
          \advance\!!dimena by-\FigWidth
          \noindent\hskip\!!dimena
        \fi
     \fi
     \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%

Regards,
BG

Re: calculations

[Henning Hraban Ramm]

Am 2006-09-20 um 00:40 schrieb nico:

> \figurewidth is not a dimension. I guess the following should work:
>
> \def\LPscale{.6315789} % downscale the image
>      \ifvmode
>         \getfiguredimensions[\bufferprefix
> lilypond-\the\lily!figures.pdf][]%
>         \leavevmode%
>         \newdimen\FigWidth
>         \newdimen\FigWidthReal=\figurewidth
>         \FigWidth=\dimexpr(\LPscale\FigWidthReal)
>         \ifdim\FigWidth>\localhsize
>           \!!dimena=\localhsize
>           \advance\!!dimena by-\FigWidth
>           \noindent\hskip\!!dimena
>         \fi
>      \fi

Thank you very much, that works indeed.

>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%

But here \dimexpr is nonsense (should have seen that before).
But "scale=1000\LPscale" just concatenates the two "strings", and TeX  
doesn't seem to reckognize a *

How can I multiply two values? Di I need some expansion magick or  
just something like "eval()"?


Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[Vit Zyka]

Henning Hraban Ramm wrote:
> Am 2006-09-20 um 00:40 schrieb nico:
> 
>> \figurewidth is not a dimension. I guess the following should work:
>>
>> \def\LPscale{.6315789} % downscale the image
>>      \ifvmode
>>         \getfiguredimensions[\bufferprefix
>> lilypond-\the\lily!figures.pdf][]%
>>         \leavevmode%
>>         \newdimen\FigWidth
>>         \newdimen\FigWidthReal=\figurewidth
>>         \FigWidth=\dimexpr(\LPscale\FigWidthReal)
>>         \ifdim\FigWidth>\localhsize
>>           \!!dimena=\localhsize
>>           \advance\!!dimena by-\FigWidth
>>           \noindent\hskip\!!dimena
>>         \fi
>>      \fi
> 
> Thank you very much, that works indeed.
> 
>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
> 
> But here \dimexpr is nonsense (should have seen that before).
> But "scale=1000\LPscale" just concatenates the two "strings", and TeX  
> doesn't seem to reckognize a *

\def\LPscale{.6315789pt}
scale=\withoutpt\the\dimexpr\LPscale*1000\relax

Vit

> How can I multiply two values? Di I need some expansion magick or  
> just something like "eval()"?
> 
> 
> Greetlings from Lake Constance!
> Hraban
> ---
> http://www.fiee.net/texnique/
> http://contextgarden.net
> http://www.cacert.org (I'm an assurer)
> 
> _______________________________________________
> ntg-context mailing list
> ntg-context@ntg.nl
> http://www.ntg.nl/mailman/listinfo/ntg-context
> 

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Re: calculations

[Peter Rolf]

Henning Hraban Ramm wrote:
> Am 2006-09-20 um 00:40 schrieb nico:
> 
>> \figurewidth is not a dimension. I guess the following should work:
>>
>> \def\LPscale{.6315789} % downscale the image
>>      \ifvmode
>>         \getfiguredimensions[\bufferprefix
>> lilypond-\the\lily!figures.pdf][]%
>>         \leavevmode%
>>         \newdimen\FigWidth
>>         \newdimen\FigWidthReal=\figurewidth
>>         \FigWidth=\dimexpr(\LPscale\FigWidthReal)
>>         \ifdim\FigWidth>\localhsize
>>           \!!dimena=\localhsize
>>           \advance\!!dimena by-\FigWidth
>>           \noindent\hskip\!!dimena
>>         \fi
>>      \fi
> 
> Thank you very much, that works indeed.
> 
>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
> 
> But here \dimexpr is nonsense (should have seen that before).
> But "scale=1000\LPscale" just concatenates the two "strings", and TeX  
> doesn't seem to reckognize a *
> 
> How can I multiply two values? Di I need some expansion magick or  
> just something like "eval()"?

\numexpr should work here

  ..[scale=\numexpr1000\LPscale\relax]%

Greetings, Peter
> 
> 
> Greetlings from Lake Constance!
> Hraban
> ---
> http://www.fiee.net/texnique/
> http://contextgarden.net
> http://www.cacert.org (I'm an assurer)
> 
> _______________________________________________
> ntg-context mailing list
> ntg-context@ntg.nl
> http://www.ntg.nl/mailman/listinfo/ntg-context
> 
> 

Re: calculations

[Henning Hraban Ramm]

Am 2006-09-21 um 21:12 schrieb Peter Rolf:

>>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
>
> \numexpr should work here
>   ..[scale=\numexpr1000\LPscale\relax]%

thank you, that seemed what I looked for, but:
! You can't use `\numexpr' in horizontal mode.


BTW, Hans' hint "sx=\LPscale" doesn't seem to do anything.


Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[Peter Rolf]

Henning Hraban Ramm wrote:
> Am 2006-09-21 um 21:12 schrieb Peter Rolf:
> 
>>>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
>> \numexpr should work here
>>   ..[scale=\numexpr1000\LPscale\relax]%
> 
> thank you, that seemed what I looked for, but:
> ! You can't use `\numexpr' in horizontal mode.
>
One of my favourite errors. Everytime it occurs I'm a bit puzzled, as
I've no general solution for this. I can only tell you what I do in such
a case.

- check every parameter of the expression

If the expression itself is ok

- check the correct grouping of prior commands (boxes, conditionals,..)
- try to calculate the expression before you pass it
  \newcount\Myscale
  \Myscale\numexpr1000\LPscale\relax
  ..[scale=\the\Myscale]

But in the end it is more try and error than a systematic action.
If there is a more general approach to solve this, I would be happy to
hear it.

Greetings, Peter

> 
> BTW, Hans' hint "sx=\LPscale" doesn't seem to do anything.
> 
> 
> Greetlings from Lake Constance!
> Hraban
> ---
> http://www.fiee.net/texnique/
> http://contextgarden.net
> http://www.cacert.org (I'm an assurer)
> 
> _______________________________________________
> ntg-context mailing list
> ntg-context@ntg.nl
> http://www.ntg.nl/mailman/listinfo/ntg-context
> 
> 

Re: calculations

[Hans Hagen]

Peter Rolf wrote:
> Henning Hraban Ramm wrote:
>   
>> Am 2006-09-21 um 21:12 schrieb Peter Rolf:
>>
>>     
>>>>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
>>>>>           
>>> \numexpr should work here
>>>   ..[scale=\numexpr1000\LPscale\relax]%
>>>       
>> thank you, that seemed what I looked for, but:
>> ! You can't use `\numexpr' in horizontal mode.
>>
>>     
> One of my favourite errors. Everytime it occurs I'm a bit puzzled, as
> I've no general solution for this. I can only tell you what I do in such
> a case.
>
> - check every parameter of the expression
>
> If the expression itself is ok
>
> - check the correct grouping of prior commands (boxes, conditionals,..)
> - try to calculate the expression before you pass it
>   \newcount\Myscale
>   \Myscale\numexpr1000\LPscale\relax
>   ..[scale=\the\Myscale]
>
> But in the end it is more try and error than a systematic action.
> If there is a more general approach to solve this, I would be happy to
> hear it.
>
> Gr
some day soon:

\def\integer#1{\lua{tex.sprint(math.floor(#1))}

scale=\integer{1000*\LPscale}

Hans

-- 

-----------------------------------------------------------------
                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                             | www.pragma-pod.nl
-----------------------------------------------------------------

Re: calculations

[Henning Hraban Ramm]

Am 2006-09-25 um 11:46 schrieb Peter Rolf:

>>>>>      \externalfigure[\lily!img][scale=\dimexpr(1000\LPscale)]%
>>> \numexpr should work here
>>>   ..[scale=\numexpr1000\LPscale\relax]%
>>
>> thank you, that seemed what I looked for, but:
>> ! You can't use `\numexpr' in horizontal mode.
>>
> One of my favourite errors. Everytime it occurs I'm a bit puzzled, as
> I've no general solution for this. I can only tell you what I do in  
> such
> a case.
> - check every parameter of the expression
> If the expression itself is ok
> - check the correct grouping of prior commands (boxes,  
> conditionals,..)
> - try to calculate the expression before you pass it
>   \newcount\Myscale
>   \Myscale\numexpr1000\LPscale\relax
>   ..[scale=\the\Myscale]
> But in the end it is more try and error than a systematic action.
> If there is a more general approach to solve this, I would be happy to
> hear it.
>

I think I tried everything but didn't get it to work.
For the moment I use:
\def\LPscale{0.6315789} % downscale the image
\def\LPkscale{632}
% doesn't work: \def\LPkscale{\numexpr1000\LPscale\relax}

But anyway - my problem is caused by LilyPond not obeying its size  
commands in EPS mode, so the simple scaling doesn't help...

Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[Taco Hoekwater]

Hi,

Henning Hraban Ramm wrote:
> 
> I think I tried everything but didn't get it to work.
> For the moment I use:
> \def\LPscale{0.6315789} % downscale the image
> \def\LPkscale{632}
> % doesn't work: \def\LPkscale{\numexpr1000\LPscale\relax}

Missed this thread so far, but how about this?

   \edef\LPkscale{\the\numexpr1000\LPscale\relax}

Cheers, Taco

Re: calculations

[Henning Hraban Ramm]

Am 2006-09-26 um 08:53 schrieb Taco Hoekwater:

>> I think I tried everything but didn't get it to work.
>> For the moment I use:
>> \def\LPscale{0.6315789} % downscale the image
>> \def\LPkscale{632}
>> % doesn't work: \def\LPkscale{\numexpr1000\LPscale\relax}
>
> Missed this thread so far, but how about this?
>    \edef\LPkscale{\the\numexpr1000\LPscale\relax}

Thank you.
That doesn't run on an error, but scales way too much.
With
\def\LPscale{0.6315789}
the command should have the same effect as
\def\LPkscale{632}

But
\edef\LPkscale{\the\numexpr1000\LPscale\relax}
seems to scale about 100 times too much.

I simply(?!?) want to multiply some floating point value with 1000 to  
set the "scale" parameter of \externalfigure.
Why ist this so difficult?

Is there a book or tutorial on TeX as a programming language somewhere?



Greetlings from Lake Constance!
Hraban
---
http://www.fiee.net/texnique/
http://contextgarden.net
http://www.cacert.org (I'm an assurer)

Re: calculations

[Peter Rolf]

Hi Hraban,

Henning Hraban Ramm wrote:
> Am 2006-09-26 um 08:53 schrieb Taco Hoekwater:
> 
>>> I think I tried everything but didn't get it to work.
>>> For the moment I use:
>>> \def\LPscale{0.6315789} % downscale the image
>>> \def\LPkscale{632}
>>> % doesn't work: \def\LPkscale{\numexpr1000\LPscale\relax}
>> Missed this thread so far, but how about this?
>>    \edef\LPkscale{\the\numexpr1000\LPscale\relax}
> 
> Thank you.
> That doesn't run on an error, but scales way too much.
> With
> \def\LPscale{0.6315789}
> the command should have the same effect as
> \def\LPkscale{632}
> 
> But
> \edef\LPkscale{\the\numexpr1000\LPscale\relax}
> seems to scale about 100 times too much.
>
maybe

\numexpr1000\dimexpr\LPscale\relax\relax

I have a good feeling about it ;)

> I simply(?!?) want to multiply some floating point value with 1000 to  
> set the "scale" parameter of \externalfigure.
> Why ist this so difficult?
>
Because there is no normal float type in TeX like in common programming
languages. Also all calculation is limited by \maxdimen.

> Is there a book or tutorial on TeX as a programming language somewhere?
>
I like 'Tex by Topic' alot. Don't know if that fits your needs.

http://archive.contextgarden.net/message/20060901.140544.1fe86b32.en.html


Greetings, Peter

> 
> 
> Greetlings from Lake Constance!
> Hraban
> ---
> http://www.fiee.net/texnique/
> http://contextgarden.net
> http://www.cacert.org (I'm an assurer)
> 
> _______________________________________________
> ntg-context mailing list
> ntg-context@ntg.nl
> http://www.ntg.nl/mailman/listinfo/ntg-context
> 
> 

Re: calculations

[Hans Hagen]

Peter Rolf wrote:
>
> I like 'Tex by Topic' alot. Don't know if that fits your needs.
>
> http://archive.contextgarden.net/message/20060901.140544.1fe86b32.en.html
>   
that ons is ok (apart from a buggy index) and i use that most of the time

it also helps to have the tex book around 

the advanced tex book is also ok but rather plain tex 

Hans 

-----------------------------------------------------------------
                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                             | www.pragma-pod.nl
-----------------------------------------------------------------